Variable condenser



Aug. 6, 1940. I. w. EGERLAND 2,210,029"

vARIABLEfcoNDENsER Original Filed Feb. 25, 1956 INVENTof-Q WOL FGA/V6 EGERLAND ATTORNEY Patented Aug. 6, 1940 PATENT OFFICE VARIABLE coNDENsER Wolfgang Egerland, Berlin, Germany, assignor to,A Siemens and Halske, Aktiengesellschaft,

Berlin-Siemensstadt, of Germany Application February 25, 1936, Serial No. 65,554 l9e3n5ewed July 15, 1939. In Germany March 9,

15 Claims.

l ing, in which:

Fig. 1 is a sectionalview of a condenser of this invention having a dielectric which has a stepped cross-section;

Fig. 2 is a sectional view of a condenser having a wedge-shaped dielectric cross-section;

Fig. 3 is a curve of variable condensers as known in the prior art; while Fig. 4 is a curve of a variable condenser according to this invention. l5 Compression type of variable condensers are known in the prior art in which flat and horizontally disposed intermediate dielectricv layers are provided to correspond to the at and horizontally disposed conductive coats or plates.

The capacity of condensers of this kind is increased in proportion to the movement of the variable conductive coat or plate as it is changed so as to be at a closer proximity to the fixed conductive coat or plate. However, the capacity 25 value does not rise in direct proportion to the reduction. of the distance, in fact, it grows ln accordance with a function as approximately illustrated by the curve in Fig. 3.

It will thus be noted from the above mentioned curve that as soon as the capacity has assumed a certain magnitude (point A, Figure 3), the growth becomes very marked with even a slight variation of the distance. Now, such a circuit change involves a number oi serious drawbacks, 35 for example, if with a certain previously adjusted capacity, there is brought. about a slight alteration of the distance, caused by the shock or percussion of the condenser, the resultant change in capacity will be found to -be inadmissi- 40 bly high. In other words, condensers of this sort can be actually utilized only inside a comparatively small range of regulation.

Now, the'present invention discloses a condenser in which the above mentioned drawbacks are obviated. The shape 'of the capacity rate of l change curve is made far more favorable, and as a result the utilizable regulating range of the condenser is increased.

This desired rate'of capacity change is obtained by having the dielectric located at lthe various points where it is in contact with a conductive coat made at least partly angular with reference to the horizontal line. Preferably, the dielectric is constructed so that it presents a cross-section which is stepor wedge-shaped, or

(C1. iis-41.5)

is bounded according to a definite predetermined curve. 'I'he stationary conductive coat or plate its shaped so as to match the curve of the dielecric.

Especially where recourse is had to a wedgeshaped, or curvilinearly bounded or contoured dielectric, a capacity rate of change graph presenting a fairly continuous and uniform shape as shown in Fig. 4 is obtained. What can be seen from this curve is that the utilizable regulation range of a condenser according to the invention is substantially flattened.

Figures l and 2 illustrate two exemplied embodiments of the invention.

Referring to Fig. l, I denotes the dielectric which presents a stepped or terraced cross-sectional iorm. Between the dielectric I and a filler compound 2, which, for instance, could also consist of the same material as the dielectric, and which is provided in order to obtain rectangular construction elements, there is arranged the ilxed coat 3 which is likewise stepped. The movable coat 4 is adjusted by V,means of a set screw 5, arranged to run in a threaded hole in insulating base Il.

`Referring to Fig. 2, 6 denotes the dielectric which has a cone or wedge-shaped cross-section.

. Between the said dielectric 6 and the filler mass 1 is the iixed coat 8. 9 denotes the non-stationary coat; I0 is the set screw, and Il the insulating base or mounting;` plate.

I claim: l

1. A variable condenser of the solid dielectric type comprising a ilat insulating base, a fixed plate secured to and spaced away from said base, a movable plate spaced away, secured to and hinged at one end of said base, said xed plate having its plane decrease in its spacing away from said base from a point where said movable plate isl hinged and secured to said base, said movable plate having its plane normally increasing in its spacing away from said base after leaving .the point where it is hinged and secured thereto, `a solid dielectric interposed between said Xed and movable plates, and means for varying the capacity of said condenser by movement of said movable plate.

2. A variable condenser of the solid dielectric type comprising a flat insulating base, a xed plate secured to and spaced away from said base, a movable plate spaced away, secured to and hinged at one end of said base, said fixed plate having its plane vdecrease in its spacing away from said base after leaving a point where said movable plate is hinged and secured to said base,

said movable plate having its plane normally increasing in its space away from said base after leaving the point where it is hinged and secured thereto, a solid dielectric interposed between said fixedl and movable plates, the outside surface oi which lies in a plate substantially parallel to the surface of said flat base, and means for varying the capacity of said condenser by movement of said movable plate.

3. A variable condenser of the solid dielectric type comprising a flat insulating base, a xed plate secured to and spaced away from said base, a movable plate spaced away, secured to and hinged at one end of said base, said xed plate having its plane forming a Wedge-shaped space which decreases in its spacing away from said base from a point where said movable plate is hinged and secured to said base, said movable plate having its plane normally increased in its spacing away from said base after leaving the point where it is hinged and secured thereto, a solid dielectric interposed between said fixed and movable plates, and means for varying the ca pacity of said condenser by movement of said movable plate.

4. `A variable condenser of the solid dielectric type comprising a flat insulating base, a xed plate secured to and spaced away from said base, a movable plate spaced away, secured to and hinged at one end of said base, said iixed plate having its plane forming a step-like space which decreases in its spacing away from said base after leaving a point where said movable plate is hinged and secured to said base, said movable plate having its plane normally increasing in its spacing away `from said base after leaving the point where it is hinged and secured thereto, a solid dielectric interposed between said xed and movable plates, and means for varying the capacity of said condenser by movement of .said movable plate.

5. A variable condenser of the solid dielectric type comprising a flat insulating base, a xed plate secured to and spaced away from said base, a movable plate spaced away, secured to and hinged at one end of said base, said fixed plate having its plane form a plurality of step-like spaces which decrease in its spacing away from said base after leaving a point where said movable plate is hinged and secured to said base, said movable plate having Aits plane normally increasing in its spacing away from said base after leaving the point where it is hinged and secured thereto, a solid dielectric interposed between said fixed and movable plates, and means for varying the capacity of said condenser by movement of said movable plate.

6. A variable condenser of the solid dielectric type comprising a at insulating base, a xed plate secured to and spaced away from said base, a movable plate spaced away, secured to and hinged at one end of said base, said fixed plate having its plane continuously and uniformly decrease in its spacing away from said base from a point where said movable plate is hinged and secured to said base, said movable plate having its plane normally increasing in its spacing away from said base after leaving the point Where it is hinged and secured thereto, a solid dielectric interposed between said iixed and movable plates, and means comprising a thread in said base andl a screw cooperating with said movable plate and the thread in said base for varying the capacity of the condenser.

7. A variable condenser of the solid dielectric type comprising an insulating base, a xed plate secured to and spaced away from said base, a movable plate spaced away, secured to and hinged at one end of said base, said xed plate having its plane decreasing in its spacing away from said base from a point where said movable plate is hinged and secured to said base, said movable plate having its plane normally increasing in its spacing away from said base after leaving a point where it is hinged and secured thereto, a solid dielectric interposed between said fixed and movable plates, and means for varying the capacity of said condenser comprising a thread in said base and a screw cooperating with said movable plate and the thread in said base.

8. A variable condenser of the solid dielectric type comprising a flat insulating base, a xed plate secured to and spaced awayfrom said base, a movable plate spaced away, secured to and hinged at one end of said base, said fixed plate having its plane forming a plurality of step-like spaces which decrease in its spacing away from said base after leaving a point where said movable plate is hinged and secured to said base, said movable plate having its plane normally increasing in its spacing away from said base after leaving the point where it is hinged and secured having its plane forming a wedge-shaped spacel which decreases in its spacing away from said base from a point where said movable plate is hinged and secured to said base, said movable plate having its plane normally increasing in its spacing away from said base after leaving the point where it is hinged and secured thereto, a solid dielectric interposed between said fixed and movable plates, and means comprising a thread in said base and a screw cooperating with said movable plate and the thread in said base for varying the capacity of the condenser.

10. A variable condenser of the solid dielectricA type comprising an insulating base, a xed plate secured to and spaced away from said base, a movable metallic plate spaced away, secured to and hinged at oneend of said base, said fixed plate having its plane form a plurality of steplike spaces which decrease in its spacing away from said base after leaving a point where said movable plate is hinged and secured to said base, the movable plate having its plane normally increase in its spacing away from said base after leaving a point where it is hinged and secured thereto, a solid dielectric interposed between said iixed and movable plates, a lling compound interposed between the underside of saic Xed plate and said base, and means for varying the capacity of said condenser by movement of said variable plate.

11. In a variable condenser, a first metal electrode, a second metal electrode xed at one end with respect to said rst electrode, a solid dielectricv interposed between said'irst and second electrodes, said solid dielectric increasing in thickness from the iixed end of said second electrode, and means for moving said second electrode throughout the remainder of its unxed length with respect to the rst electrode and dielectric.

12. A variable condenser comprising, a base member, a rst metal electrode forming an inclined plane with respect to said base member and secured thereto, a second metal electrode ixedly hinged to said base at one end with respect to the highest point of said ilrst electrode, a solid dielectric interposed between said rst and second electrodes, said solid dielectric having one surface parallel to the base member and its other surface parallel to the surface of the first metal electrode, and means formoving said second electrode throughout the remainder of its unflxed length with respect to said ilrst electrode and solid dielectric.

13. A variable condenser comprising, a base member, a first metal electrode secured to said base member, a second spring-like metal electrode xedly hinged to said base at one end with respect to said rst electrode, .a solid dielectric .interposed between said first and second elecmovable plate.

l5. A variable condenser of the solid dielectric` type comprising, a base member, a fixed plate secured to and spaced away from said base, a movable plate spaced away, secured to and hinged at one end of said base, said xed plate having its plane decrease in its spacing away from said base from a point`where said movable plate is hinge. and secured to said base, said movable plate having its plane normally increasing in its spacing away from said base after leaving the point where it is hinged thereto,.a Solid dielectric having a cross-section which varies in thickness interposed between said fixed and movable plates, a lling compound interposed between the underside of said xed plate and said base to insure said fixed plate of retaining its form when said movable plate is moved, and means for vary-- ing the capacity of said condenser by movement of said movable plate.

WOLFGANG EGERLAND. 

